In sites of emergency medical care for diseases (such as a brain disorder) or accidents (such as a traffic accident), it is of crucial importance to secure blood flow to the brain of a patient. If blood flow to the brain is not sufficient, a patient may have a serious aftereffect in the brain even if his or her life is saved. Whether blood flow to the brain is sufficient or not can be determined on the basis of the strength of pulse (blood pressure) of the carotid artery.
In sites of emergency medical care, blood pressure measurement using a sphygmomanometer cannot be conducted in many cases depending on the circumstances. In such a case, a doctor, an emergency medical technician or the like typically determines whether or not blood flow to the brain of a patient is sufficient by palpating the carotid artery of the patient with fingers.
There is also a device for detecting a pulse wave of the carotid artery of a patient (refer to the Patent Document 1). Note that a pulse wave refers to variation in the volume of body tissues caused by motion of blood in a form of a waveform from the body surface.
Furthermore, the pulse wave can also be measured at the radial artery in the wrist, and there have been increasing needs for quantitative measurement of pulse strength or the like. The palpation of the radial artery has been known as pulse diagnosis in Chinese medicine and has been deemed to allow the holistic health condition to be grasped.